Lake quillwort (Isoetes lacustris, Sp. Pl.: 1100 (1753))

Family: Isoetaceae

Author: L.

Bibliography: Sp. Pl.: 1100 (1753)

Year: 1753

Status: accepted

Rank: species

Genus: Isoetes

Vegetable: False

Observations: Europe to Siberia, Greenland, C. & E. Canada to NC. & NE. U.S.A.

Description

Lake quillwort, scientifically known as Isoetes lacustris, is an intriguing and discrete aquatic plant, flourishing in the quiet freshwater habitats of Europe, Siberia, Greenland, and stretching across Central and Eastern Canada to the northeast and north-central United States.

Belonging to the Isoetaceae family, Lake quillwort garners attention for its quill-like leaves that rise from a stumpy base rooted in the sediment of freshwater lakes. Typically found in shallow waters, these evergreen perennials display a vibrant green hue, contributing to the lush underwater scenery in their native regions.

The leaves of Isoetes lacustris, which can reach different lengths depending on water depth and other environmental factors, form a rosette pattern. This unique arrangement aids in its identification among enthusiasts and botanists alike. Besides, its root system and rhizomes play a pivotal role in anchoring the plant securely to the lake bed, making it resilient in its often dynamic aquatic environment.

Historically documented in 1753 by the renowned botanist Carl Linnaeus, Lake quillwort continues to be a subject of study for a modern audience fascinated by its evolutionary adaptations and ecological contributions. This species has managed to thrive across a broad geographical range, indicative of its robustness and adaptability.

Isoetes lacustris serves as an ecological keystone, contributing significantly to the biodiversity and health of aquatic ecosystems. Its presence helps maintain water clarity and provides habitat for various aquatic organisms. Moreover, it acts as a bioindicator, offering insights into the water quality and environmental conditions of its habitat.

In sum, Lake quillwort, Isoetes lacustris, enriches the aquatic landscapes where it is found, showcasing resilience and ecological importance. It invites ongoing study and appreciation for its unique characteristics and the vital role it plays in freshwater ecosystems.

Common Names

Eng: isoète lacustre, lake quillwort, quillwort, common quillwort, deepwater quillwort, large-spored quillwort, merlin’s-grass, western lake quillwort, western quillwort
Deu: see-brachsenkraut, see-brachsenkraut oder gewöhnliches brachsenkraut, seebrachsenkraut, gewöhnlich-brachsenkraut
Dan: sortgrøn brasenføde
Lav: gludsporu ezerene
Nld: grote biesvaren
Fra: isoète des lacs, isoète lacustre, isoète des étangs, isoète hiéroglyphique, isoète à grosses spores
Pol: poryblin jeziorny
Swe: styvt braxengräs, vårtsporigt braxengräs
Sme: čohkkesnjuovvi
Cym: diosglys merllyn, gwair merllyn
En: Lake quillwort, Western Lake Quillwort, Isoète lacustre, Quillwort, Common Quillwort, Merlin’s-grass, Deepwater quillwort, Large-spored quillwort, Western quillwort
Ar: إسويط بحيري
Be: Палушнік азёрны
Bg: Езерен полушник
Cs: Šídlatka jezerní
Da: Sortgrøn Brasenføde
Nl: Grote biesvaren
Et: Järv-lahnarohi
Fi: Tummalahnanruoho
Fr: Isoète lacustre, Isoète des lacs, Isoète des étangs, Isoète hiéroglyphique, Isoète à grosses spores
De: Gewöhnliches Brachsenkraut, See-Brachsenkraut, See-Brachsenkraut oder Gewöhnliches Brachsenkraut, Seebrachsenkraut, Gewöhnlich-Brachsenkraut
Is: Vatnalaukur
It: Calamaria lacustre
Lv: Gludsporu ezerene
Lt: Ežerinė slepišerė
Se: Čohkkesnjuovvi
Fa: ایستس لاکستریس
Pl: Poryblin jeziorny
Ru: Полушник озёрный
Sv: Styvt braxengräs, Vårtsporigt braxengräs
Uk: Молодильник озерний
Cy: Gwair merllyn, Diosglys Merllyn

Synonyms

• Isoetes lacustris var. strictum (J.Gay)
• Isoetes lacustris var. minor (Milde)
• Isoetes lacustris var. stricta (Motelay & Vendryès)
• Isoetes lacustris var. falcatum (Fliche)
• Isoetes lacustris var. elatior (Fliche)
• Isoetes moorei (Moore)
• Isoetes lacustris var. gracilis (Gray)
• Isoetes lacustris var. fragilis (Gray)
• Isoetes lacustris subsp. brochonii ((Motelay) R.C.V.Douin)
• Calamaria lacustris ((L.) Kuntze)
• Isoetes hieroglyphica (A.A.Eaton)

Distribution

• Altay (native)
• Austria (native)
• Baltic States (native)
• Belgium (native)
• Bulgaria (native)
• Central European Rus (native)
• Connecticut (native)
• Czechoslovakia (native)
• Denmark (native)
• East European Russia (native)
• Finland (native)
• France (native)
• Føroyar (native)
• Germany (native)
• Great Britain (native)
• Greenland (native)
• Iceland (native)
• Ireland (native)
• Irkutsk (native)
• Labrador (native)
• Maine (native)
• Manitoba (native)
• Masachusettes (native)
• Michigan (native)
• Minnesota (native)
• Netherlands (native)
• New Brunswick (native)
• New Hampshire (native)
• New Jersey (native)
• New York (native)
• Newfoundland (native)
• North European Russi (native)
• Northwest Territorie (native)
• Norway (native)
• Nova Scotia (native)
• Ontario (native)
• Poland (native)
• Prince Edward I. (native)
• Québec (native)
• Rhode I. (native)
• Saskatchewan (native)
• Spain (native)
• Sweden (native)
• Switzerland (native)
• Tennessee (native)
• Vermont (native)
• Virginia (native)
• West Siberia (native)
• Wisconsin (native)

Additional Images

Fruit

Taken Aug 4, 2022 by Sylvain Piry (cc-by-sa)

Taken Aug 4, 2022 by Sylvain Piry (cc-by-sa)

Habit

Taken Jul 11, 2013 by Tela Botanica − Liliane Roubaudi (cc-by-sa)

Taken Jul 11, 2013 by Tela Botanica − Liliane Roubaudi (cc-by-sa)

Taken Sep 13, 2016 by Tela Botanica − Jean-Christophe RAGUE (cc-by-sa)

Taken Jul 11, 2013 by Tela Botanica − Liliane Roubaudi (cc-by-sa)

Taken Sep 13, 2016 by Tela Botanica − Jean-Christophe RAGUE (cc-by-sa)

Leaf

Taken Aug 4, 2022 by Sylvain Piry (cc-by-sa)

Taken Jul 28, 2022 by Gerd Suessbier (cc-by-sa)

Taken Jul 30, 2017 by Marcel Ambühl (cc-by-sa)

Taken Jul 20, 2022 by Edward Byrne (cc-by-sa)

Other

Taken Aug 15, 2005 by Photoflora – Jean-Luc TASSET (©)

Taken Jan 1, 1970 by Photoflora – L’Abbé COSTE (©)

Taken Jan 1, 1970 by Photoflora – L’Abbé COSTE (©)

© copyright of the Board of Trustees of the Royal Botanic Gardens, Kew.

Sources

• WFO (No URL)
• IPNI (No URL)
• GBIF (https://www.gbif.org/species/2688270)
• POWO (http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:310437-2)
• PlantNet (https://identify.plantnet.org/species/the-plant-list/Isoetes lacustris L.)

Specifications

Growth habit: Graminoid

Growth

Ph maximum: 5.5

Ph minimum: 5.0

Light: 7

Atmospheric humidity: 9

Bloom months: [‘aug’, ‘sep’, ‘oct’, ‘nov’]

Soil nutriments: 2